"If you want to securely erase a hard drive, it's not as easy as writing it over with zeroes. Sure, an "erased" hard drive like this won't boot up your computer if you just plug it in again. But if the drive falls into the hands of a specialist with a scanning tunneling microscope, they can tell the difference between "this was a 0, overwritten by a 0" and "this was a 1, overwritten by a 0".
There are programs advertised to "securely erase" hard drives using many overwrites of 0s, 1s, and random data. But if you want to keep the secret on your hard drive secure against all possible future technologies that might ever be developed, then cover it with thermite and set it on fire. It's the only way to be sure."
There have been no cases of anyone ever restoring a zeroed hard drive. It's utter bullshit. Especially these days with our precision aligned platters and insane densities.
I wish I had this advice two years ago when I was starting my own company. I didn't pick up my eggs, bread or conquering hero and now I'm a washed up bum.